Conjoined Twins: Definition and Statistics
Rough Outline: Conjoined Twins
Definition and Statistics
* Identical twins that are physically joined at birth * Referred to as Siamese twins which comes from the famous twins Eng and Bunker who were born in Siam (Thailand) in 1811
Twinning occurs in one of two ways:
1) a woman releases two eggs instead of the usual one 2) a woman produces only one egg that divides after fertilization
In the case of conjoined twins
* A woman only produces one single egg, which does not fully separate after fertilization * Developing embryo starts to split into identical twins during the first few weeks after conception but the process stops before its complete * Another theory suggests that two separate embryos may somehow fuse together in early development
Symptoms
* There aren’t any specific signs and symptoms that a woman is carrying conjoined twins * As with other twin pregnancies, the uterus may grow more rapidly than expected, and mothers of twins may also have more fatigue, nausea and vomiting early in the pregnancy * Conjoined twins are classified by where they are joined * Medical experts use words to identify conjoined twins that contain “pagus” meaning “fastened” in Greek * Thoracopagus twins are joined at the chest, share a heart and may also share a liver and upper intestine * Omphalopagus twins are joined near the bellybutton, share the liver, and some share the lower part of the small intestine (ileum) and colon * Pygopagus twins are joined at the base of the spine, share the lower gastrointestinal tract, and a few share the genital and urinary organs * Ischiopagus twins are joined at the pelvis, share the lower gastronintestinal tract, as well as the genital and urinary tract organs * Craniopagus twins are joined at the heard, share a skull and possibly brain tissue, some also share cerebral cortex—the part of the brain that plays a central role in memory, language and
Definition and Statistics
* Identical twins that are physically joined at birth * Referred to as Siamese twins which comes from the famous twins Eng and Bunker who were born in Siam (Thailand) in 1811
Twinning occurs in one of two ways:
1) a woman releases two eggs instead of the usual one 2) a woman produces only one egg that divides after fertilization
In the case of conjoined twins
* A woman only produces one single egg, which does not fully separate after fertilization * Developing embryo starts to split into identical twins during the first few weeks after conception but the process stops before its complete * Another theory suggests that two separate embryos may somehow fuse together in early development
Symptoms
* There aren’t any specific signs and symptoms that a woman is carrying conjoined twins * As with other twin pregnancies, the uterus may grow more rapidly than expected, and mothers of twins may also have more fatigue, nausea and vomiting early in the pregnancy * Conjoined twins are classified by where they are joined * Medical experts use words to identify conjoined twins that contain “pagus” meaning “fastened” in Greek * Thoracopagus twins are joined at the chest, share a heart and may also share a liver and upper intestine * Omphalopagus twins are joined near the bellybutton, share the liver, and some share the lower part of the small intestine (ileum) and colon * Pygopagus twins are joined at the base of the spine, share the lower gastrointestinal tract, and a few share the genital and urinary organs * Ischiopagus twins are joined at the pelvis, share the lower gastronintestinal tract, as well as the genital and urinary tract organs * Craniopagus twins are joined at the heard, share a skull and possibly brain tissue, some also share cerebral cortex—the part of the brain that plays a central role in memory, language and